Traditional aqueous cleaning is a process of major importance for textiles which routinely uses large quantities of water in combination with appropriate detergent formulations. These formulations are complex, but typically comprise surfactants, with or without a series of enzymes to provide a biological action in the removal of certain stains, together with oxidising or bleaching components and their associated activators, to neutralise highly coloured stains. In addition, the formulations generally also include builders to control water hardness, anti-redeposition additives to prevent re-settling of removed soil back on to the textile surface, perfumes to ensure a suitable level of fragrancy, and optical brighteners to further mask the effects of redeposition—particularly on white garments.
In conventional aqueous cleaning processes, the detergent formulation is usually added as an all-in-one dosing, or there may be a wash and rinse split, wherein a softener or other formulated additive is added as a separate stage. The problem that arises, however, is that there is a significant dilution of the components in the detergent formulation at the textile surface as the wash cycle progresses, with the consequence that good cleaning occurs at the expense of the removal of anti-redeposition additives, perfumes and optical brighteners from the cleaned textile. These three parts of the detergent formulation, most particularly, are instrumental in meeting consumer needs when cleaning quality is judged. Hence, in conventional aqueous cleaning processes, all-in-one detergent formulations are effectively overloaded with these chemicals, in order to ensure that they remain present in sufficient quantities on the final cleaned textile surface. Naturally, this increases the overall detergent dosage level in the wash and the cost of the detergent formulation itself.
WO-A-2007/128962 discloses a cleaning process that employs a formulation which requires the use of only limited amounts of water, thereby offering significant environmental benefits. Thus, the inventors of WO-A-2007/128962 disclosed a method for cleaning a soiled substrate, the method comprising the treatment of the moistened substrate with a formulation comprising a multiplicity of polymeric particles or beads. Whilst the method of WO-A-2007/128962 can employ similar detergent formulations to traditional aqueous cleaning processes—at significantly reduced dosage levels—there is still an inherent inefficiency to all-in-one dosing.
These difficulties are therefore addressed in WO-A-2011/128680, which describes a modified detergent dosing process for use when cleaning using polymeric beads. In this method, the detergent formulation is split into its constituent chemical parts, with these being added at different times during the cleaning process, specifically during the wash and rinse sections of the cycle. In this way, not only is the overall chemical loading reduced, but the more expensive components of the formulations can be added when they are likely to be most effective for cleaning performance. As a consequence, considerable cost savings are achieved when compared with conventional all-in-one detergents.
The methods disclosed in WO-A-2007/128962 and WO-A-2011/128680 use only a limited amount of water, thereby providing environmental benefits. Whilst there are, therefore, significant advantages over the methods of the prior art, there still remains a difficulty, in that the re-use of the same detergent formulation components over several washes is not possible, thus leading to expensive repeat dosing from wash to wash. Consequently, the present inventors have sought to address this problem by providing a modified cleaning composition wherein detergent components are immobilised on the polymeric beads used in the method of WO-A-2007/128962, thereby providing improved cleaning performance, as well as the ability to re-use these detergent components over multiple washes.
WO-A-2012/104861 relates to the use of a PVC surface co-immobilised with multiple enzymes for the removal of stains which is useful in the field of washing or cleaning household textiles, and provides processes for the preparation and use of the PVC surfaces. It appears that the inventors are concerned only with the treatment and use of PVC surfaces, typically in the form of a container and brush, with formulations comprising multiple enzymes, and do not consider the use of cleaning materials in the form of polymeric beads.